Combination oil well derrick and tilting construction boom



June 1959 H. J. WOOLSLAYER ET AL 2,889,898

COMBINATION on. WELL DERRICK AND TILTING CONSTRUCTION BOOM Filed June13,1957

2 Sheets-Sheet 1 m w mam 6 3 2 WWW. m H h m M mm I. j Ww P r kwfiyw mUnited States Patent Ofifice 2,889,898 Patented June 9, 1959 COMBINATIONOIL WELL DERRICK AND TILT IN G CDNSTRUCTION BOOM Homer J. Woolslayer,Cecil Jenkins, and Charles D.

Iddings, Tulsa, Okla, assignors to Lee C. Moore Corporation, Pittsburgh,Pa., a corporation of Pennsylvania Application June 13, 1957, Serial No.665,565

Claims. (Cl. 189-15) This invention relates to oil well derricks, andmore particularly to those in which a tilting mast is formed from a pairof spaced upright columns connected by a. truss.

In certain cases, especially in off-shore drilling, it would bedesirable to be able to use the drilling mast as a construction boombefore drilling is started. A wellknown type of drilling mast lendsitself to such a combination of functions because the mast is hinged toa base so that the mast can be swung up to upright position from areclining position in front of the base. By providing means for tiltingthe mast backward from its upright position to any desired angle, themast could serve as a construction boom except that the bracing acrossthe back of the mast would interfere with the movements of the travelingblock used as a construction hoist.

It is among the objects of this invention to provide an oil well derrickwhich can be used both for drilling and for construction work, which isadequately braced for both operations, which includes bracing that canbe shifted from one position to another depending on whether the mast isbeing used for drilling or as a tilting boom, and in which the shiftablebracing can be handled easily and quickly.

In accordance with this invention, a pair of laterally spaced uprightcolumns that are rigidly connected at their upper ends have their lowerends hinged to a base. The columns normally are held upright to form adrilling mast. At such times, a truss located between the columns hasits opposite ends detachably connected to the backs of the columns tobrace the back of the mast. The front of the mast is left open to permitpipe to be racked beside the mast. Means are provided for tilting themast backward from its upright position so that it can be used as aconstruction boom with the traveling block hanging straight down fromthe upper end of the tilted boom. To prevent the truss from interferingwith the traveling block, suspension members extend forward from theends of the truss and are pivotally connected to means supported by theinner sides of the columns midway between their fronts and backs.Therefore, when the truss is disconnected from the backs of the columns,it can be swung down and forward and then up to a position between thefronts of the columns, where the truss can be connected to the columnsagain to brace the front of the mast. Consequently, the mast is bracedwhether it is used for drilling or as a construction boom, but thebracing does not interfere with either operation- The preferredembodiment of the invention is illustrated in the accompanying drawings,in which: v 7

Fig. 1 is a side view of our derrick showing the'mast in drillingposition, but indicating in dotted lines its use as a constructon boom;

Fig. 2 is a fragmentary rear view of the mast;

Fig. 3 is an enlarged fragmentary rear view of the mast showing thetruss connected to the backs of the columns;

Fig. 4 is a horizontal section through the mast immediately abovemembers 31 of Fig. 3; and

Fig. 5 is a vertical section taken on the line VV of Fig. 3.

Referring to Figs. 1 and 2 of the drawings, an oil well derrick mast isformed from a pair of upright structural steel columns, each of which isconstructed from a pair of front legs 1 rigidly connected to a pair ofback legs 2 by suitable braces 3. The lower ends of the columns arespaced a considerable distance apart and their upper ends are spacedapart a somewhat lesser distance. The upper ends are rigidly connectedby a framework 4 that supports the usual crown block 5, from which atraveling block 6 is suspended between the columns by lines 7 connectedwith a draw-works 8 on a suitable base 9. The lower ends of the columnsare hinged to the base, and the mast is held upright by a gin pole 16mounted on the base behind it.

For at least the major portion of its height the front of the mast isfree of cross braces between its columns, but the usual racking platform12 projects from the fronts of the columns at a predetermined heightabove the base. The capacity of the mast is increased materially bybracing the columns by means of a truss 13 spanning the space betweenthem above the gin pole. The mast can be lowered into reclining positionin front of the base by means of the traveling block and a sling line(not shown) in a well-known manner. The mast is also raised fromreclining to upright position by the traveling block pulling on thesling line. It will be seen that the mast, as described thus far, isused in conventional manner for drilling oil wells.

There are times when it is desirable to also use this mast as aconstruction boom, such as when the mast is intended for offshoredrilling. In that case, the base may be mounted on one end of a barge 14or on a platform supported above the water by piling. The mast can beused as a boom by connecting suitable block and tackle 15 to the upperend of the mast and to a lufling hoist 16 a considerable distance infront of the mast. Tension is put on the tackle by means of the hoist tohold the mast while the rear legs of the gin pole are disconnected fromthe base and swung backward over the rear edge of the base or allowed toextend down through openings in it. The hoist is then operated to allowgravity to tilt the mast over backward so that its upper end will belocated behind the base and underlying structure, as shown in dottedlines in Fig. 1. This will cause the traveling block to swing out of theback of the mast above truss 13 and hang straight down from the crownblock behind the mast. It will be seen, however, that when the mast ispulled back toward upright position with a load hanging from thetraveling block, the truss at the back of the mast may interfere withthe load or the block.

It is therefore a feature of this invention that the truss can be movedinto another position where it will still brace the mast but will notinterfere with its use as a construction boom. For this purpose, asshown in Fig. 3, the truss is constructed from the heavy top and bottomhorizontal members 20, such as I-beams, rigidly connected by verticaland inclined braces 21. The top and bottom members or chords of thetruss are the same length, so that the truss is rectangular to enable itto fit either side up between the columns. The opposite ends of thechords are connected by bolts 22 to the adjoining ends of shorthorizontal braces 23 and 24 welded across the back of each column. Thesebraces preferably are the same size and shape as the chords of thetruss, except they are shorter. The lower braces are longer than theupper ones to compensate for the inclination of the columns. The trussis slightly shorter than the distance between the columns at trusslevel. It will be seen that this construction provides heavy bracingacross the back of the mast, which stiifens it and thereby increases itsworking capacity.

Projecting forward from the opposite ends of the truss are suspensionmembers. Preferably, these members consists of rigid bars 26 welded tothe ends of chords 28. As shown in Fig. 5, the upper bars are inclineddownward toward the center of the mast and the lower bars are inclinedupward. The pair of converging bars at each end of the truss have theirinner ends rigidly connected together and to a trunnion 27 that projectsout into a bearing 28 mounted on the cross bracing 3 of the adjoiningcolumn midway between its front and back. Consequently, if the truss isdisconnected from the backs of the columns, the bearings will permit itto swing down between the columns, where it will be supported by thetrunnions.

When it is desired to do this, the traveling block is connected with thetop of the truss to support it while it is disconnected from braces 23and 24 and then the block is lowered to allow the truss to swing downand forward into horizontal position between the columns. The travelingblock then is disconnected from the truss and connected with itsopposite side, following which the block is raised in the mast to swingthe truss forward and up between the front sides of the columns. Upwardmovement of the truss is limited by stops 29 that project from the innerends of horizontal braces 30 welded to the front legs of the columnslike the corresponding braces 23 at the back of the mast, which supportsimilar stops 3.1. The ends of the truss can be bolted to front braces30 and lower braces 32 to brace the front of the mast. With the truss atthe front of the mast, the mast can now be used as a boom withoutinterference from the truss, and yet the benefit of the truss willcontinue to be obtained. To convert from a boom to a drilling mast, themast is pulled upright, the back legs of the gin pole anchored to thebars, and the truss returned to the back of the columns.

If it were not for the pivotal support of the truss at bearings 28 inthe mast while the truss is disconnected from the columns, it would beextremely difficult to handle the truss and guide it into correctposition. The pivotal connection restricts the movement of the truss toa predetermined arc and therefore controls its move ment from one sideof the mast to the other. This guiding or control also assures alignmentof the bolt holes of the truss chords and the adjoining column braces,so that the truss can be quickly and easily bolted to either the frontor the back of the mast. No manual guiding of the truss into place isrequired, as it is controlled entirely by lowering and raising thetraveling block.

According to the provisions of the patent statutes, we have explainedthe principle of our invention and have illustrated and described whatwe now consider to represent its best embodiment. However, we desire tohave it understood that, within the scope of the appended claims, theinvention may be practiced otherwise than as specifically illustratedand described.

We claim:

1. A combination oil Well derrick and tilting construction boom,comprising a base, a pair of laterally spaced upright columns rigidlyconnected at their upper ends, means hinging the lower ends of thecolumns to the base, means normally holding the columns upright to forma drilling mast adapted to support its working loads along a verticalline between the columns, a truss located between the columns, meansdetachably connecting the opposite ends of the truss to the backs of thecolumns to brace the back of the mast, means connected to the mast totilt it backward as a construction boom, suspension members extendingforward from the ends of the truss, and axially aligned means supportedby the inner sides of the columns midway between their fronts and backsand pivotally connecting said members to the columns on a single commonaxis to permit the truss to be swung down and forward bodily and then upto a bottom side up position between the fronts of the columns, thetruss being connectable to the columns when it is in said forwardposition to brace the front of the mast while it is used as a boom.

2. In an oil well drilling mast mounted for tilting backward from asubstantially vertical drilling position to an inclined hoistingposition, the combination with a pair of laterally spaced uprightcolumns rigidly connected at their upper ends, of a truss locatedbetween the columns, means detachably connecting the opposite ends ofthe truss to the backs of the columns to brace the back of the mast,suspension members extending forward from the ends of the truss, andaxially aligned means supported by the inner sides of the columns midwaybetween their fronts and backs and pivotally connecting said members tothe columns on a single common axis to permit the truss to be swung downand forward bodily and then up to a bottom side up position between thefronts of the columns, the truss being connectable to the columns whenit is in said forward position to brace the front of the mast.

3. The combination recited in claim 2, in which the truss has parallelupper and lower longitudinal members connected by braces, and the frontsand backs of the columns are provided with pairs of parallel horizontalmembers that form continuations of said longitudinal members when thetruss is connected to them,

4. In an oil well drilling mast mounted for tilting backward from asubstantially vertical drilling position to an inclined hoistingposition, the combination with a pair of laterally spaced uprightcolumns rigidly connected at their upper ends, of a truss locatedbetween the columns, means detachably connecting the opposite ends ofthe truss to the backs of the columns to brace the back of the mast,rigid suspension members projecting forward from the ends of the truss,a pair of axially aligned bearings supported by the inner sides of thecolumns midway between their fronts and backs, and trunnions mounted inthe bearings and secured to the front ends of said suspension members topermit the truss to be swung down and forward bodily and then up to abottom side up position between the fronts of the columns, the trussbeing connectable to the columns when it is in said forward position tobrace the front of the mast.

5. The combination recited in claim 4, in which a pair of saidsuspension members at each end of the truss converge toward the trunnionahead of them.

References Cited in the file of this patent UNITED STATES PATENTS2,168,837 York Aug. 8, 1939 2,345,253 Funk Mar. 28, 1944 2,780,326Woolslayer Feb. 5, 1957 2,781,108 Selberg et a1. Feb. 12, 1957 OTHERREFERENCES World Oil Publication, May 1957, p. 137.

